Synchronized drive



2 Sheets-Sheet 1 R. BLOW SYNCHRONIZED DRIVE Filed Feb. 8, 1943 March 6,1945.

March 6, 1945, R. BL-ow 2,371,023

SYNCHRONIZED DRIVE Filed Feb.l 8, 1943 2 ShebS-Sheet 2 Patented Mar. 6,1945 SYNCHRONIZED DRIVE Richard Blow, Chicago, Ill., assignor to W. F.

Hall Printing Company, Chicago, Ill., a corporation of IllinoisApplication February 8, 1943, Serial No. 475,190

Claims.

The present invention relates to synchronized drives for co-relating theoperation of two machines or mechanisms so that said machines ormechanisms will function synchronously as a single unit. Moreparticularly this invention relates to synchronizing of the drive shaftsof two separate machines and wherein each of the machines includes aseparate driving motor, together with electric control circuits for themotors by virtue of which one machine may be operated independently ofthe other.

One of the objects of this invention is to provide an improvedelectrically controlled synchronized drive of the character describedwherein the control circuit for one machine is interconnected with thecontrol circuit of the other machine in a manner to preclude operationof one machine unless the other machine is operating.

Another object is to provide an improved synchronized drive,characterized by the provision of two separate electrical controlcircuits interconnected in a manner to preclude operation of one machineunless the other machine is operating, and wherein said other machinemay be operated independently of the said one machine.

A further object is to provide an improved synchronized drive of thecharacter indicated wherein two separate machines are provided withelectrical control circuits and separate motors for respectively drivingseparate shafts joined together by a free wheeling clutch and whereinone motor may be energized for driving its corresponding shaft only whenthe controlling circuit for the other motor is completed and driving itscorresponding shaft and wherein the said one motor serves to drive itsshaft at a speed slightly in excess of the speed of the other shaft toinsure maintaining synchronized rotation of the two shafts.

A stil] further object is to provide an improved synchronized drive ofthe character indicated, in-

cluding interconnected electrical control circuits' by virtue of whichone machine isnormally permitted only to rotate at slow speed when theother machine is idle and by virtue of which both machines may bejointly operated synchronously at a relatively high rate of speed.

A still further object is to provide a novel synchronized drive ofthecharacter indicated which is relatively simple, inexpensive and capableof giving reliable service.

Other objects and advantages of this invention will be apparent from thefollowing description, taken in connection with the accompanyingdrawings in which:

`gathering and binding machines.

Fig. 1 is a schematic wiring diagram, including control mechanismembodying the present invention.

Fig. 2 is a fragmentary plan view' of the free wheeling clutchinterconnecting the two shafts of the respective machines together withcircuit making devices.

Fig. 3 is a view in side elevation of the free wheeling clutch andcircuit making devices, representing an enlargement of the correspondingparts seen schematically in Fig. 1 of the drawings.

Fig. '4 isan end elevational View of the clutch housing, taken asindicated on line 4 4 on Fig. 3.

For purposes of clarity and to insure a proper and full understanding ofmy invention I will hereinafter describe the same as employed inconnection with a gathering machine and binding machine. As is wellknown, these machines are utilized in the binding of leaflets, catalogs,books and the like, wherein a multiplicity of pages or sectionsconstituting a book, catalog or the like are rst assembled, in properorder, in loose fashion, and are then transmitted as separate, completeunits, by means of a conveyor on the gathering machine, for delivery toa conveyor on the book binding machine, where suitable adhesive and/ orother binding is applied to the unit of loose pages for connecting thempermanently together.

The assembled unit of loose pages, as they are handled by the bindingmachine, are trimmed and adhesive and/or other binding is applied to thehinge edge in a manner well understood in the art. Inasmuch as these tworespective machines, namely the gathering machine and binder, form nopart of the present invention, I have accordingly omitted allillustration and reference thereto with the exception of the two shaftsof the respective machines and their interconnection by which they aresynchronized and which shafts for convenience I have designated hereinas GI and BI respectively.

It may be understood that these shafts are driven through suitablegearing, not shown, from separate electrical motors designatedrespectively as G2 and B2. The' shafts Gl and BI are disposed in axialalignment with their ends in relatively close relationship to eachother. Each of said shafts are provided with means, not shown, foroperating conveyor devices on the respective Therefore, by maintainingthe shafts GI and Bl in synchronized relationship to each other it istherefore possible to synchronize the relationship of the gatheringconveyor to the conveyor of the binding machine. two conveyors theeiiiciency of the two machines is considerably increased, and permittingdispensing with the manual services of several .persons which wereheretofore necessary to transmit the assembly of loose pages of thecatalog, boo-k, etc., from the gathering machine and placing them on theconveyor of the binding machine.

A single conveyor combining the functions of the gathering and bindingmachines could not be practically utilized because at times it is deusired that the binding machine be permitted to function whollyindependently of the gathering machine. Generally, however, it isdesirable that the two machines function'in `timed or synchronousrelation to each other. There may be, however, certain special occasionswhere it would be desired to operate the gathering machine independentlyof the binding machine and or such condition a separate control circuit,other than shown in the diagram herein,l may be employed. In the properuse of the two machines for performing a continuous operation in thegathering and binding of books, catalogs and the like, it is highlydesirable that the machines be so interconnected that the gatheringmachine cannot function unless the binding machine is alreadyfunctioning.

Furthermore it is desirable that the gathering machine be provided withsuitable controls which will permit it to be periodically stopped orarrested while the binding machine continues in operation. Hence, it isof utmost importance that when the gathering machine is restarted, whilethe binding machine is operating, that it start in phase or synchronizedrelation to the binding machine, otherwise the conveyors of the twomachines would not be correlated so as to function as a single conveyorfor handling continuously the gathered assemblies of loose sheets orpages of a catalog or book for transmission from the gathering machineto the binding machine.

By virtue of my present invention, as will hereinafter be more fullydescribed, it is now possible to always maintain proper synchronizedrelationship of the conveyors of the two machines each time that thegathering machine is started during the time that the binding machine isalready operating. To facilitate a clear understanding and to avoidconfusion, reference will hereinafter be made to the parts of thebinding machine as the main elements such as the main motor, main driveshaft, etc., and the reference characters will be preceded by the letter13, whereas corrsponding parts of the gathering machine will be i'designated as auxiliary motor, auxiliary shaft, etc., and said partswill in so far as practical be accorded the same numbers, preceded bythe letter G.

Mounted on the end of the main drive shaft Bl is a free wheeling clutch3, which is connected to said shaft Bi for rotation therewith. Thecorresponding end of the shaft Gl is disposed in such correlation to theclutch that when said shaft Gi is idle the clutch 3 and the shaft Bl arestill capable of free rotation. When, however, the shaft Gl is driven,it cannot rotate at a speed greater than the speed of travel of theclutch due to the interlocking action of the clutch, which prevents theshaft, or to say it differently, the conveyor of the gathering machinefrom traveling at a speed greater thanthe speed of the conveyor of thebinder. The clutch will, however, permit the drive shaft GI to catch upto the speed of rotation of the drive shaft Bl of By synchronizing thedrives of the the binding machine. When the shaft GI4 is driven, it isto be understood that due to suitable gearing or drive connectionsemployed, it will be caused to rotate at a speed slightly greater thanthe speed of rotation of drive shaft BI, and as a result thereof theshaft Gl tends to drive the shaft BI through the clutch 3.

In the wiring diagram I have indicated two panels, one designatedGathering controller and the other Binding controller, in connection.with which certain devices of the respective control circuits areillustrated. It is to be vunderstood that each of the motors G2 and B2are of the synchronous three phase type and include respectively powerline connection G4, G5, and G6 and B4, B5 and B6. Each of the motorsinclude adjustable field resistances indicated at G7 and B1, adapted tobe cut into and out of the electrical circuits for obtaining operationof the respective motors at a desired speed. For this purpose I employin the circuits of the respective motors a pair of switches indicated atG8 and B3. In the power lines G4 and G6, and in B4 and B of therespective controls, I employ a pair of switches indicated respectivelyat G9 and B9.

Because of the great length of the gathering machine it is desirablethat the operation of the machine be capable of control at severalspaced apart points along the length thereof, and for this purpose thereis provided a plurality of manually operated switches indicated at 5.Another man ually operated switch similar to switch 5 and designated Seis preferably located near the juno tion of the conveyors of thegathering and bin-ding machines. I also employ a master switch f3adjacent the junction of the conveyors of the two machines by virtue ofwhich both machines may be simultaneously arrested as distinguished fromswitches 5 and 5a which merely make or break the electrical circuits forcontrolling the gathering machine. l

Located on the binding machine is a suitable starting and stoppingswitch indicated at 'l whichd is connected in series with the switch 6and thus necessitates the closure of both of the switches in order tocomplete the electrical circuit for opera tion of the binding machine,as will be presently described.

Connected in the electrical control circuit of the gathering machine aretwo contact brushes,

indicate-d at 9 and l0, positioned for contacting collector ringsindicated at Il and i2, mounted upon and rotatable With the gatheringmachine drive shaft GI. A mounting member i3 is secured on the shaft Gland carries a panel i4 of insulating material on which is supported apair of spaced apart, longitudinally extending, contact points I5 andi6. The contact point i5 is connected by a conductor wire l1 to thecollector ring I i, while the contact point i6 is connected by conductorwire I8 to collector ring i2. `It will new be apparent that the twocontact points l5 adjacent end of the housing of the clutch 3.

and i5, by virtue of their mounting on the panel l fi rotatable as aunit with the gathering machine drive shaft Gi. Mounted on the adjacentend of the housing of the clutch 3 is an arcuate conductor plate 2li ofhigh .electrically` conductive material such as brass and which, inturn, is mounted on an insulating disk 2| carried on the The plate 2d,in certain positions of angular relationships of the shafts Gl and BI,serves to bridge the contact points l5 and I6 and complete portions ofan electrical circuit of the gathering controller and which undercertain conditions makes it possible for the two shafts GI and Bl torotate in synchronism.

As above stated the shaft GI may at times be stationary during the timethat drive shaft Bl of the binding machine is rotating. It is desired,however, that when the drive shaft Gi rotates that it does so insynchronized relationship to the drive shaft Bl. Hence, when the shaftGI is stationary while shaft Bl! rotates, the contact plate 20 willperiodically bridge the contacts I5 and IG but it will perform nofunction in the control circuit of the gathering machine because thecircuit is open at other places, as will be described.

The control circuit of the binder controller ine cludes coils B80, BSC,and BH3C, which serve to control the switches B8, B3 and Bill. Theconductor wires indicated at BAIL Vand BBL may be connected to the samesources of power supply as the motor power lines indicated at B4 and B6respectively. It is to be understood that the coils B'SC, B'C and BMC,together with their correw sponding switches BS and B9 anw Bill, areconventional relays and when the respective coils are energized thecorresponding switches are closed.

The relay coil BSC, through its switches B8 controls the resistance oithe motor B2. The coil BBC, however, is connected in the electricalcircuit of the gathering controller and is only energized when thecircuit of the gathering controller is completed, hence, the switches B8are normally open. Therefore, when the motor B2 is rst energized theresistances B1 cause the motor B2 to be driven at a slow speed. It maybe understood that when the resistances are short circuited by theclosing of switches B3, the motor is then driven at a relatively highspeed.

In the electrical circuit cf the gathering controller the coilsdesignated as GBC and GSC control respectively the switches G8 and G9.The coil GlilC controls the switch Gio while the coil GHC controls theswitch Gli. It will also noted that the coil GSC controls the switch GEXwhich is connected in series with the coil G! iC. The main power linesdesignated at GliL and GBL are adapted to be connected to the respectivepower terminals to which the power lines G4 and G5 of the motor G2 areconnected.

A relay coil 25 controls a switch 25a, which is connected in theelectrical control circuit of the gathering controller. and serves topermit completion of the circuit of vthe gathering machine only when theelectrical circuit of the binding machine is completed.

I will now describe the operation of the respective circuits of thebinding machine and the gathering machine and the operation of thecircuit of the binding machine, will be rst described. When the mainswitch E is closed the starter switch 'l is then moved to a closedposition. Current then flows from the source of power supply throughsupply line BAL, switch l, through the conductor wire 3l?, main switch5, through conductor wire 3l, through the coils BSC and BIOC to thepower supply line BL. The coils BSC and BIQC thus become energized andclose the switches B9 and BMJ. The switches B9 thus complete the circuitof the motor B2, while the switch BH) controls a separate circuitincluding electrically operated devices such as solenoids which in turncontrol the brakes on the binding machine and when the circiut iscompleted through the switch B10 the brakes on the machine are releasedand as soon as the switch BIO opens the circuit the brakes are applied.

The closing of the switches B9 in the main power supply line B4 and BSof the motor B2, thus permits the motor to start up at slow speed, andfor purposes of illustration it may be stated that the speed of themotor is such that the main drive shaft Bl is rotated at approximately20 R. P. M. The binding machine will continue to operate at this speedunlessI affected by closing of the circuit of the gathering machine, orunless either of the switches li or 'l are opened, thereby breaking thecircuit to the motor B2.

In this connection it may be pointed o-ut that the relay and itscorresponding switch 25 functions as an interlocking control. The coil25 is connected by conductor wires 33 and 34 to the power supply linesB5 and B6 respectively, of the source of supply for the motor B2. Theswitch Bit in addition to its other function also serves to control thecompletion of the circuit including the coil 25. Obviously when the coil25 is energized the switch 25a is closed so as to complete or conditiona portion of the control circiut of the gathering machine. It will benoted in this respect that the relay coil 25 cannot be energized untilthe coil B9 has been energized to close its corresponding switches BS,one of which is located in the main power supply line BB of the circuitof the motor B2, ahead of the connection with the conductor wire 34.

As above stated the gathering machine cannot be operated as long as theswitch 25a of the interlocking control is open, but as soon as thebinder is operating switch 25a is closed. When itv is desired to operatethe gathering machine, during the time that the binder machine isoperating, the switches 5 and 5a must first all be closed because theseswitches are all connected in series with each other as above stated,and are located at spaced apart joints along the conveyor of thegathering machine.

When these switches 5 and 5a are closed, (subject to the control by theclutch 3) current is supplied from the main supply line GAL through theswitches 5 and te through a conductor wire 35, through the switch 2eaand conductor wire 31 through the coils G90 and GIGC and conductor wire3S, to the brush 9 and through the collector ring il and conductor wireIT to the contact i5, through the bridging plate 2B, back through thecontact point l@ and its conductor wire I8 and collector ring l2 throughthe brush IB and conductor wire 38, to the main power supply line GGL.It may be well to here state that this circuit, with switches E inclosed, is completed only when the shaft B! carrying the clutch 3rotates and disposes the contact plate 2S in position to bridge the endsof the contact points l5 and i6. When the coils GSC and GQC areenergized they close respectively, their corresponding switches G3 andGli?, switches G9 being connected in two oi the main power lines G4 andto the motor G2. The rnotor G2 is thus started at a relatively slowspeed. Upon closing of the switch Gil the relay coil GB is energized bybeing coupled in a circuit with the conductors 3? and and this energizedcoil then closes the switches G3, associated with the resistances of themotor and by virtue of which the resistances are short circuited so asto cause the motor to rotate at relatively high speed. The energizing ofthe coil GEC also results yin the closing of the switch resulting inenergizing oi the coil Gl EC connected by the conductor wire El,directly to the main power supply line GSL.

When the coil G! 1C is energized it closes the switch GH and thus servesto hold or maintain the electrical circuit including the coils GSC,GlllC, GSC and GHC, The coil GHC is a low voltage relay coil and may forconvenience be termed a holding relay because of its function, servingto hold the electricalcircuit after it has once been established.

'When the coils GSC and GMC become energized, it may be understood thatthere is a delaying action before the coil GSC is energized whichcontrols the short circuiting of the resistances of the motor G2, andduring this period current also flows from conductor wire 37, through aconductor wire dil through the relay coil BSC of the binder controlcircuit and back through a conductor wire il and thence to the mainpower supply line GL in a manner described in connection with theenergizing of the coils of the relays GSC and GMC. When the coil BSC ofthe binder control circuit is energized the switches B8 associated withthe resistances of the motor B2 are closed and results in shortcircuiting of the resistance to cause the binder motor E2 to rotate athigh speed.

It may be assumed that for all practical pur-- poses the respectivecoils GiBC of the gathering machine and BSC of the binder machineoperate substantially simultaneously so that the shafts Gl and Bl aresimultaneously brought up to high speed. Because the shaft Gi rotates ata speed slightly in excess of the high speed of the shaft Bl, there willbe a tendency for the shaft Gl to drive the shaft Bi through the clutch.'i and thereby constantly maintains proper relationship of the contactpoints and i5 with the bridging plate 2:3, carried by thefree wheelingclutch 3.

When any one of the switches 5 or 5EL is opened, the circuit to thegathering machine, including the motor, is immediately broken, and alsoresults in (ie-energizing of the coils BSC, causing the rho- 'tor B2 ofthe binding machine to rotate at relatively low Speed because of theopening of the switches Bi?, placing the resistances back in the motorfield.

It will also be apparent that when both of the circuits are completedand the shaft Gl and El are synchronously driven, both of the machinesmay be simultaneously arrested by the opening of the main switch e.

Although I have shown and described a pren ferred embodiment of myinvention, manifestly it is capable of modification and rearrangement ofparts without departing from the spirit and scope thereof. I do not,therefore, wish to be understood as'limiting this invention to theprecise form herein disclosed, except as I may be so limited in theappended claims.

I claim as my invention:

l. In a synchronized drive of the character described, the combinationof a main drive shaft, a main motor for driving said shaft, auxiliarydrive shaft, an auxiliary motor for driving said auxiliary shaft. at aspeed slightly in excess of the speed cf rotation of said main driveshaft, said shafts being rotatable in the same direction and beingdisposed in axial alignment in close end to end relation. and a freeWheeling clutch carried by and positively connected to the main driveshaft for rotation therewith and disposed in position to be operablyengaged and driven by said auxiliary drive shaft.

2, In a synchronized drive of the character de scribed, the combinationof a main drive shaft, a main motor for driving said shaft, an auxiliarydrive shaft, an auxiliary motor for driving said auxiliary shaft, saidshafts being rotatable lin the saine direction and being disposed inaxial alignmen in close end to end relation, a free wheeling clutchcarried by and positively connected to the main drive shaft for rotationtherewith and disposed in position to be operably engaged and driven bysaid auxiliary drive shaft, electrical control circuits for each of saidmotors, a manually operated switch in each of sai-d circuits, and meansresponsive to energization of the control circuit for the main motor forcompleting a portion of the control circuit of said auxiliary motor.

3. In a synchronized drive of the character described, the combinationof a main drive shaft, a main motor for driving said shaft, an auxiliarydrive shaft, an auxiliary motor for driving said auxiliary shaft, saidshafts being rotatable in the same direction and being disposed in axialalignment in close end to end relation, a free wheeling clutch carriedby and positively connected to the main drive shaft for rotationtherewith and disposed in position to be operably engaged and driven bysaid auxiliary drive shaft, electrical control circuits for each of saidmotors, a manually operated switch in each of said circuits, and a relayconnected for energization by the control circuit of the main motor andserving to control said control circuit of the auxiliary motor, wherebysaid auxiliary motor is adapted to be driven only when theelectricalcircuit for the main motor is closed and when the switch of saidauxiliary circuit is closed.

Ll. In a synchronous drive of the character described, the combinationof a main drive shaft, a

I' main motor for driving said shaft, an auxiliary drive shaft, anauxiliary motor for driving said auxiliary shaft, said shafts beingrotatable in the same direction and being disposed in axial alignment inclose end to end relation, a free wheeling clutch carried by andpositively connected to the main drive shaft for rotation therewith anddisposed in position to be operably engaged and driven by said auxiliarydrive shaft, electrical control circuits for each of said motors, amanually operated control switch in each of said circuits, meansinterconnecting said circuits for precluding completion of the auxiliarycircuit except when said main circuit is completed, a bridging contactplate carried on the end face of said clutch adjacent tbe auxiliarydrive shaft and connected in said auxiliary circuit, and a pair ofseparate contacts carried on and rotatable with said auxiliary driveshaft and connected to the respective collector rings, said contactsbeing positioned to simultaneously engage said contact plate on theclutch when the latter turns relatively to the auxiliary drive shaft forcompleting a portion of the auxiliary circuit, whereby the switch of theauxiliary circuit permits breaking of said auxiliary circuitindependently of the main circuit and whereby said interconnecting meansprecludes completion of said auxiliary circuit said main circuit isopen.

5. In a synchronous drive of the character de scribed, the combinationof a main drive shaft, a main motor for driving said shaft, an auxiliarydrive shaft, an auxiliary motor for driving said auxiliary shaft, at aspeed slightly in excess of the speed of rotation of said main driveshaft, said shafts being rotatable in the same direction and beingdisposed in axial alignment in close end to end relation, a freewheeling clutch carried by and positively connected to the main driveshaft for rotation therewith and disposed in position to be operably`engaged and driven by said auxiliary driveshaft, electrical controlcircuits for each of said motors, a manually operated control switch ineach of said circuits, means interconnecting said circuits forprecluding completion of the auxiliary circuit except when said maincircuit. is completed, a bridging contact plate carried on the end faceof said clutch adjacent the auxiliary drive shaft, a pair of slip ringcollectors on the auxiliary drive shaft and connected in said auxiliarycircuit, and a pair of separate contacts carried on and rotatable withsaid auxiliary drive shaft and connected to the respective collectorrings, said contacts being positioned to simultaneously engage saidcontact plate on the clutch when the latter turns relatively to theauxiliary drive shaft for completing a portion of the auxiliary circuit,whereby the switch of the auxiliary circuit permits breaking of saidauxiliary circuit independently of the main circuit and whereby saidinterconnecting means precludes completion of said auxiliary circuitwhen said main circuit is open.

6. In a synchronized drive of the character described, the combinationof a main drive shaft, a main motor for driving said shaft, an auxiliarydrive shaft, an auxiliary motor for driving said auxiliary shaft, saidshafts being rotatable in the same direction and being disposed in axialalignment in close end to end relation, a free wheeling clutch carriedby and positively connected to the main drive shaft for rotationtherewith and disposed in position to be operably engaged and driven bysaid auxiliary drive shaft, electrical control circuits for each of saidmotors, a manually operated switch in each of said circuits, meansresponsive to energization of the control circuit for the main motor forcompleting a portion of the control circuit of said auxiliary motor, anelectrical resistance in the main motor for causing said motor to benormally driven at slow speed, and means in the auxiliary circuitadapted when said circuit is completed to short circuit said resistancefor causing said main motor to be driven at high speed.

7; In a synchronized drive of the character described, the combinationof a main drive shaft, a main motor for driving said shaft, an auxiliarydrive shaft, an auxiliary motor for driving said auxiliary shaft, saidshafts being rotatable in the same direction and being disposed in axialalignment in close end to end relation, a free wheeling clutch carriedby and positively connected to the main drive shaft for rotationtherewith and disposed in position to be operably engaged and driven bysaid auxiliary drive shaft, electrical control circuits for each of saidmotors, a manually operated switch in each of said circuits, meansresponsive to energization `of' the control circuit for the main motorfor completing a portion of the control circuit of said auxiliary motor,an electrical resistance in the main motor for causing said motor to benormally driven at slow speed, means in the auxiliary circuit adaptedwhen said circuit is completed to short circuit `caid resistance forcausing said main motor to be driven at high speed, an electricalresistance in the auxiliary motor for initially causing said motor to bedriven at slow speed upon completion of the auxiliary circuit, and meansin said auxiliary circuit for short circuiting said resistance forcausing said motor to be driven at high speed.

8. In a synchronous drive of the character described, the combination ofa main drive shaft, a main motor for driving said shaft, an auxiliarydrive shaft, an auxiliary motor for driving said auxiliary shaft, at aspeed slightly in excess of the speed of rotation of said main driveshaft, said shafts being rotatable in the same direction and beingdisposed in axial alignment in close end to end relation, a freewheeling clutch carried by and positively connected to the main driveshaft for rotation therewith and disposed in position to be operablyengagedand driven by said auxiliary drive shaft, electrical controlcircuits for each of said motors, a manually operated control switch ineach of said circuits, means interconnecting said circuits forprecluding completion of the auxiliary circuit except when said maincircuit is completed, .a bridging contact plate carried on the end faceof said clutch adjacent the auxiliary drive shaft, a pair of slip ringcollectors on the auxiliary drive shaft and connected in said auxiliarycircuit, a pair of separate contacts carried on and rotatable with saidauxiliary drive shaft and connected to the respective collector rings,said contacts being positioned to simultaneously engage said Contactplate on the clutch when the latter turns relatively to the auxiliarydrive shaft for completing a portion of the auxiliary circuit, wherebythe switch of the auxiliary circuit permits breaking of said auxiliarycircuit independently of the main circuit and whereby saidinterconnecting means precludes completion of said auxiliary circuitwhen said main circuit is open, an electrical resistance in the mainmotor for causing said mo-tor to be normally driven at slow speed, andmeans in the auxiliary circuit adapted when said circuit is completed toshort circuit said resistance for causing said main motor to be drivenat high speed.

9. In a synchronous drive of the character described, the combination ofa main drive shaft, a main motor for driving said shaft, an auxiliarydrive shaft, an auxiliary motor for driving said auxiliary shaft, at aspeed slightly in excess of the speed of rotation of said main driveshaft, said shafts being rotatable in the same direction and beingdisposed in axial alignment in close end to end relation, a freewheeling clutch carried by and positively connected to the main driveshaft for rotation therewith andl disposed in position to be operablyengaged and driven by said auxiliary drive shaft,electrical controlcircuits for each of said motors, a manually operated control switch ineach of said circuits, means interconnecting said circuits forprecluding completion of the auxiliary circuit except when said maincircuit is completed, a bridging contact plate carried on the end faceof said clutch adjacent the auxiliary drive shaft, a pair of slip ringcollectors on the auxiliary drive shaft and connected in said auxiliarycircuit, a pair of separate contacts carried on and rotatable with saidauxiliary drive shaft and connected to the respective collector rings,said contacts being positioned to simultaneously engage said contactplate on the clutch when the latter turns relatively to the auxiliarydrive shaft for completing a portion of the auxiliary circuit, wherebythe switch of the auxiliary circuit permits breaking of said auxiliarycircuit independently of the main circuit and whereby saidinterconnecting means precludes completion of said auxiliary circuitlwhen said main circuit is open, an electrical resistance in the mainmotor for causing said motor to be normally driven at slow speed, meansin the auxiliary circuit adapted when said circuit is completed to shortcircuit said resistance for causing said main motor to be driven at highspeed, an electrical resistance -in .the rauxiliary ,motor for initially.causing said motorio be driven at slow speed upon completion ofA .theauxiliary circuit, and means in said auxiliary .circuit for shortcircuiting said resistance for causing said motor to be driven at highspeed. t

10. In a synchronized vdrive ofthe character described, the combinationof a main drive shaft, amain synchronous motor for driving said shaft,an auxiliary drive shaft, an auxiliary synchronous motor for drivingsaid auxiliary shaft, said shafts being rotatable in the same directionand being disposed in axial alignment in close end to end relation, afree wheeling` clutch carried by and positively connected to the I'naindrive shaft for rotation therewith and disposed in position to beoperably engaged and driven by said auxiliary drive shaft, electricalcontrol circuits for each of said motors, a manually operated switch neach of said circuits, and means responsive to ener gization of thecontrol circuit for the main motor for completing a porti-on ofthecontrol circuit of said auxiliary motor.

RICHARD BLOW.

